Tests find petroleum in soil around Fire House 2

By Pat Tomlinson

Published 1:56 pm, Wednesday, October 11, 2017

WILTON — An investigation by the state Department of Energy and Envioronmental Protection into last month’s oil leak on Ridgefield Road revealed concentrations of petroleum present in the soil of the town’s Fire House 2 property stemming from an unrelated incident.

Near the end of September, a DEEP investigation found that Fire House 2, which abuts the property where the oil leak occurred on Sept. 7, had abandoned oil tanks buried a foot beneath the surface in the northwest corner of its property.

“I would like to point out that any event or potential event that may compromise the quality and sustainability of the town’s natural resources is of concern to us. Therefore, the discovery of the two non-functional oil tanks warrants further investigation,” said Barry Bogle, the director of Wilton’s Health Department.

During the investigation, DEEP also identified a dry well with a direct feed to the station’s garage drain, which is not permitted under state environmental regulations.

“The ground water in the area of the station is classified at such a level that you can’t discharge water from that kind of dry well into the ground,” said Dennis Schain, a spokesperson for DEEP.

The underground tanks — one of which was 550 gallons, the other 1,000 gallons — are believed to date back to the mid-to late-1980s, Bogle said.

The problem posed by the discovery of the oil tanks is that they have been linked to soil contamination in past instances.

“Underground oil tanks have been and continue to be an issue relative to the potential for accidental discharge and the leakage of oil onto or below the ground surface,” Bogle said.

Soil samples received by the Health Department on Tuesday detected “low concentrations” of petroleum hydrocarbons around the smaller of the two oil tanks and the dry well.

The tests revealed that the soil around the 550-gallon tank and the dry well tested positive for petroleum constituents ranging from 1,140 parts per million (ppm) to 3,800 ppm and 1,420 ppm, respectively. DEEP requires municipalities to remove any soil with more than 500 ppm.

The tests found no detectable level of petroleum around the 1,000-gallon tank.

Based on the findings, the town is currently developing a plan for the investigation and removal of impacted soils in areas of the 550-gallon tank and the drywell.

After being alerted by DEEP on Sept. 21, the town immediately removed the oil tanks from the property and the department immediately stopped using the dry well, said First Selectman Lynne Vanderslice.

Additionally, a pump chamber and holding tank will need to be installed to catch any harmful byproducts from the drywell’s drain, and the preexisting dry well will need to be removed, said Vanderslice.

To avert any problems in the meantime, fire trucks will be taken to the main fire station on Danbury Road to be washed until the drainage system at Fire House 2 can be made compliant with state law.

Vanderslice estimated that DEEP’s discovery will cost the town around $50,000 in costs related to the removal of the drywall and two tanks, the reconfiguring of the drainage at the Fire Station 2, the installation of a holding tank, and for the soil testing.

Costs could be on the rise for the town, however, since the estimates provided by Vanderslice were given before the soil tests came back positive.